Thermal printing apparatuses have been developed for many uses, including the printing of various information in various type fonts on documents such as plain paper check documents, using one-time thermal transfer ribbons. The thermal transfer ribbons may contain ink of the optically readable type (OCR) or may provide magnetic ink which is machine readable (MICR).
A thermal printing apparatus capable of printing in a plurality of type fonts, such as font E-13B, is shown in U.S. Pat. No. 4,531,132, issued July 23, 1985, inventor Philip J. Wilkinson, assigned to the assignee of the present application.
Another thermal printing apparatus capable of printing in specific styles of fonts such as E-13B or OCR is shown in U.S. patent application Ser. No. 561,449, filed Dec. 14, 1983, inventors Ralf M. Brooks et al., assigned to the assignee of the present application.
The printer mechanisms which form the subject-matter of the above-referenced patent and application have been developed to print various type fonts used in financial transactions on plain paper documents such as checks using a "one-time" thermal transfer ribbon. To obtain the document throughput or speed necessary to make the item processing machines in which the printer mechanisms are to be installed commercially feasible, it is necessary that the financial font field be printed in a parallel fashion. Although the check or other document moves into the printing station in a horizontal direction, the "line" thermal printhead of the thermal printer moves in the vertical direction during the printing operation, while the check or other document remains stationary. This movement of the printhead imposes certain requirements upon the operating means for the thermal transfer ribbon in order to avoid smudging of the transferred ink on the document being printed upon, and possible breakage of the ribbon.